Liver Stiffness Assessed by Transient Elastography Overestimates Fibrosis Compared to Histology of Liver Specimens Obtained by Endoscopic Ultrasound Guided Liver Biopsy (EUS-LB)

Abstract

Introduction: In patients with chronic liver disease, endoscopic ultrasound-guided liver biopsy (EUSLB) is widely used to obtain liver histology. EUS-LB provides better diagnostic yield compared to percutaneous liver biopsy (PC-LB). Transient elastography by Fibroscan (FS), which assessed liver stiffness, and APRI score, are alternatives used to assess liver fibrosis. Previous studies showed concordance between FS and PC-LB, with FS sensitivity of 60-79% and specificity of 81-93%. However, there are no studies comparing the concordance of FS to EUS-LB. Methods: To assess the diagnostic accuracy of fibrosis assessment via FS in patients with chronic liver disease, we correlated the liver stiffness to histological stage of fibrosis in liver tissue obtained by EUS-LB. We performed an analysis of a prospectively maintained database. Between Sept 2014 and June 2018, 98 patients underwent both FS (F0 to F4 stage) and EUS-LB (Metavir score F0 to F4 stage). Amongst those only those were analyzed who had FS and EUS-LB within 180 days of each other (n=81). Results: The mean patient age was 51.4 yrs. and 59.3% were female. Fibrosis score agreement between FS and EUS-LB was 22.2 % (18/81), weighted kappa = 0.236. FS overestimated the fibrosis score in 75.3% (61/81) (p < 0.0001). FS overestimated fibrosis by one stage in 26, by two stages in 20, by three stages in 10, and by four stages in 5 cases (Table 1). In subgroup analysis of patients with NASH, FS overpredicted fibrosis more than half of the time (p < 0.0001) with minimal agreement compared to EUS-LB, weighted kappa = 0.165. FS underestimated the fibrosis in only 2.5% (2/81) cases. There were no procedure-related adverse events in the study. Conclusion: Although FS is now a widely used test to assess liver fibrosis, it fails to hold up to the same standards when compared to EUS-LB. EUS-LB provides better fibrosis assessment due to bi-lobar sampling, access to deeper tissue, and lack of operator-dependent variability. We conclude that unlike FS, which measures liver stiffness, EUS-LB assesses liver fibrosis more accurately.890 Figure 1 No Caption available.